This invention relates to air freshener gels. More particularly, this invention relates to slow diffusing solid air freshener gels formed using amylose starch as the primary gelling agent.
So-called air freshener gels have been used for a number of years to provide a relatively continuous level of perfume and/or odorant in an enclosed room. There have been a number of proposed and commercially available air freshener gels. The primary gelling agent used in most of these gels are various forms of carrageenin, a naturally occurring gelling material derived from seaweed. Although carrageenin does form a stiff gel which will dispense the perfume over an extended period of time, there are a number of disadvantages in the use of carrageenin as a primary gelling material for producing air freshener gels. The first major disadvantage is the high cost of carrageenin; second, either relatively high levels of carrageenin or additives must be used to produce a gel which has a low degree of syneresis, i.e., the appearance of free moisture on the surface of the gel; and third, carrageenin gels have a long setting time.
Although there are a number of materials which form gels, for one reason or another these materials are not particularly satisfactory for use in air freshener gel composition. However, it has been found unexpectedly that a composition utilizing from 2.5-15% amylose starch when mixed with appropriate amounts of perfume in an aqueous system produces a rigid, strong gel with substantially no signs of syneresis. These gels are inexpensive to produce and slowly release the perfume and moisture over an appropriate period of time.